B-ManFX4
Solar Enthusiast
- Joined
- Jan 17, 2022
- Messages
- 98
I have read every post in this thread. My sincere best wishes to the OP and his family. That is a horrible experience. If there is a donation web site someone please post a link - I will gladly contribute. I can't imagine the depth of the loss they are now going through. Amazing courage to post the information he has - you certainly open yourself up to question / ridicule / speculation / etc. Thanks for sharing - I am going to make a few additions to my power room based on your experience.
I myself have two 16s 304AH banks in two separate Apexium boxes. I am trying to visualize how the fuse that the fire inspector says was the root cause could have started a fire intense enough to ignite a chain reaction. In my system, the fuse is literally the last thing between the BMS and the positive battery post connection. For the fuse to blow there would have to be massive current flowing either into or out of the battery.
That leaves me with a few possibilities:
1. My inverter / chargers suffer some catastrophic failure and start dumping mega amps into the battery AND the inverter / charger AC input breakers failed to trip.
2. Something in my inverter chargers failed and the battery started dumping mega amps into them AND both battery BMS's did not disconnect AND the battery output fuses didn't blow.
3. If a single cell in the 16s string internally shorted there could be massive current flow within the battery itself - but how would the fuse at the end of the string blow? The current within the cell to cell short would be "behind" the fuse - the current would not be flowing out to the load.
In the OPs case I don't believe the fuse caused anything to happen. I believe the bank had an internal cell failure, a fire ensued, something on the load side is damaged by the fire and then started conducting hard enough to overload the fuse. Had the fuse popped or not, it would not have mattered - the excessive current draw was behind the fuse and the fire was already initiated.
On an RV forum I frequent, a member posted pictures of a LiFePO4 cell that he and his wife both saw flames shooting out of a bottom corner of the cell. The system was not in use at the time. The corner looked like a blow torch had been used from the inside out. Several others commented that "LiFePO4 can't burn like that" and his response was "My wife and I both saw the flames and I threw the entire battery outside of the RV." In the pics he posted it appeared the cell ruptured the bottom corner facing outward so the flame was not directed at the neighboring cells. I have been searching for that thread but have not had any luck finding it yet.
Based on what I have read in this thread, I am going to make a few changes and additions to my power room. These will include new ionization smoke detectors that also have a relay in the base. That relay will be wired to a Tyco 500 amp contactor placed immediately after the fuse inside each Apexium box. If either smoke detector is activated the relays will de-energize the battery circuit to the inverter / chargers. I am also going to install a ducted fan that will vent to the outside world in the hopes that a cell off-gassing event will be mitigated enough to prevent ignition or explosion.
Finally - my power room is concrete slab with 3 wood framed stud walls. I am going to sandwich 5/8" Firecode X Drywall - 1/2" cement board - 5/8" Firecode X Drywall for the three exposed wood stud walls and the ceiling. The 4th wall is cinder block so no burn potential there.
I myself have two 16s 304AH banks in two separate Apexium boxes. I am trying to visualize how the fuse that the fire inspector says was the root cause could have started a fire intense enough to ignite a chain reaction. In my system, the fuse is literally the last thing between the BMS and the positive battery post connection. For the fuse to blow there would have to be massive current flowing either into or out of the battery.
That leaves me with a few possibilities:
1. My inverter / chargers suffer some catastrophic failure and start dumping mega amps into the battery AND the inverter / charger AC input breakers failed to trip.
2. Something in my inverter chargers failed and the battery started dumping mega amps into them AND both battery BMS's did not disconnect AND the battery output fuses didn't blow.
3. If a single cell in the 16s string internally shorted there could be massive current flow within the battery itself - but how would the fuse at the end of the string blow? The current within the cell to cell short would be "behind" the fuse - the current would not be flowing out to the load.
In the OPs case I don't believe the fuse caused anything to happen. I believe the bank had an internal cell failure, a fire ensued, something on the load side is damaged by the fire and then started conducting hard enough to overload the fuse. Had the fuse popped or not, it would not have mattered - the excessive current draw was behind the fuse and the fire was already initiated.
On an RV forum I frequent, a member posted pictures of a LiFePO4 cell that he and his wife both saw flames shooting out of a bottom corner of the cell. The system was not in use at the time. The corner looked like a blow torch had been used from the inside out. Several others commented that "LiFePO4 can't burn like that" and his response was "My wife and I both saw the flames and I threw the entire battery outside of the RV." In the pics he posted it appeared the cell ruptured the bottom corner facing outward so the flame was not directed at the neighboring cells. I have been searching for that thread but have not had any luck finding it yet.
Based on what I have read in this thread, I am going to make a few changes and additions to my power room. These will include new ionization smoke detectors that also have a relay in the base. That relay will be wired to a Tyco 500 amp contactor placed immediately after the fuse inside each Apexium box. If either smoke detector is activated the relays will de-energize the battery circuit to the inverter / chargers. I am also going to install a ducted fan that will vent to the outside world in the hopes that a cell off-gassing event will be mitigated enough to prevent ignition or explosion.
Finally - my power room is concrete slab with 3 wood framed stud walls. I am going to sandwich 5/8" Firecode X Drywall - 1/2" cement board - 5/8" Firecode X Drywall for the three exposed wood stud walls and the ceiling. The 4th wall is cinder block so no burn potential there.